1. Field of the Invention The present invention relates to a mobile communication system. More particularly, the present invention relates to a method and system for managing mobility and security of an Access Terminal (AT) in a mobile communication system supporting Mobile Internet Protocol version 4 (MIPv4).
2. Description of the Related Art
In conventional mobile communication systems such as a Code Division Multiple Access (CDMA) 1× system and an Evolution Data Only (EV-DO) system, which were developed by the 3rd Generation Partnership Project 2 (3GPP2) standard group, an Access Network (AN) manages wireless resources, and a Packet Data Serving Node (PDSN), which is a separate entity of a Core Network (CN), performs a procedure associated with packet data communication.
In the conventional mobile communication system supporting Mobile Internet Protocol (MIP), research has been conducted on a scheme for offering mobility to ATs using Mobile IPv4 or Mobile IPv6. However, conventional Mobile IPv4 is unsuitable for use in the improved 3GPP2 Ultra Mobile Broadband (UMB) that is designed to transmit a large volume of data at high speed. Therefore, a plan to improve Mobile IPv4 is being investigated as one of the schemes capable of efficiently supporting UMB. When an AT moves between heterogeneous networks supporting not only UMB but also another network access technology, i.e., even when an AT moves through, for example, a UMB network and a World Interoperability for Microwave Access (WiMAX) network, there is a need for a scheme capable of efficiently supporting mobility of the AT.
Mobile IPv4, which was used in the conventional CDMA 1× system or EV-DO system, requires a long time to carry out the access and call processing process. That is, although Mobile IP, as compared with Simple IP, can provide mobility to ATs, there may be a time delay caused by one or more of a security process for mobility support, a call processing process, and database management in its access, call processing, and security processes. Therefore, there is a demand for an efficient mobility management scheme for addressing the time delay problem in the mobile communication system supporting MIP.